io.springlets.web.mvc.util.concurrency.ConcurrencyTemplate Maven / Gradle / Ivy
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package io.springlets.web.mvc.util.concurrency;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.orm.ObjectOptimisticLockingFailureException;
import org.springframework.ui.Model;
/**
* = ConcurrencyTemplate
*
* Template class that simplifies programmatic concurrency demarcation and
* concurrency exception handling.
*
* @param Generic type that indicates the type of element that should be returned after
* {@link #execute(ConcurrencyCallback)} is called.
* @author Juan Carlos García at http://www.disid.com[DISID Corporation S.L.]
*/
public class ConcurrencyTemplate {
// Logger to log possible concurrency exceptions
private static final Logger LOGGER = LoggerFactory.getLogger(ConcurrencyTemplate.class);
/**
* The element that will manage the concurrency behavior if some
* concurrency exception appears.
*/
private ConcurrencyManager manager;
/**
* Default constructor that receives all the necessary parameters.
*
* @param manager The element that will manage the concurrency behavior if some concurrency
* exception appears.
*/
public ConcurrencyTemplate(ConcurrencyManager manager) {
this.manager = manager;
}
/**
* Executes the provided action. If something goes wrong and a {@link ConcurrencyException} appears during
* the process, it delegates in the provided {@link ConcurrencyManager} to manage the concurrency behaviour.
*
* @param action The action that should be executed and that could produce a Concurrency Exception.
* @return An object with the same type as the specified in the ConcurrencyTemplate constructor
* @throws ConcurrencyTemplateException if some exception different of {@link ObjectOptimisticLockingFailureException}
* is throwed during concurrency management.
*/
public T execute(T record, Model model, ConcurrencyCallback action) {
try {
// Execute the provided action and return the result
return action.doInConcurrency(record);
} catch (ObjectOptimisticLockingFailureException ex) {
// If some Concurrency Exception appears, log the error as debug level
// and throws a custom exception that contains all the information about
// the view layer.
LOGGER.debug(ex.getLocalizedMessage());
throw new ConcurrencyException(this.manager, record, model, ex);
} catch(Exception e){
throw new ConcurrencyTemplateException(e);
}
}
/**
* Custom exception to manage concurrency template errors
*/
public static class ConcurrencyTemplateException extends RuntimeException{
/**
*
*/
private static final long serialVersionUID = -2010317519711402983L;
/**
* Default constructor
*
* @param e
*/
public ConcurrencyTemplateException(Exception e) {
super(e);
}
public Throwable getEx() {
return getCause();
}
}
}